Vapor-tube-starting device.



PATENTED OCT. 2, 1906.

' T. BODDE. VAPOR TUBE STARTING DEVICE.

APPLICATION FILED MAR. 16

UNITED STATES lPATENT OFFICE.

THEODORE BODDE, OF NEW YORK', N. Y., ASSIGNOR TOLOUIS B. MARKS,

' OF NEW YORK, N. Y.

VAPOR-TUBE-STARTING DEVICE.

Speccation of Letters Patent.

,Patented Oct. 2, 1906.

Application iiled March 16. 1904. Serial No. 198,475.

To all whom t may concern:

Be it known that I, THEoDoRE BODDE, a subject of the Queenk of theNetherlands, residing in New York city, borough of Manhattan, 1n thecounty and State of New York, have invented certainnew and usefulImprovements in Vapor-Tiibe-StartingpDevices, of which the following isa speciiication.

My invention relates to ,vapor-tubes, and more particularly to lamps andrectiiiers of mercury-vapor tubes, yand has for its object to produce ameans of readily starting such tubes with Ithe normal potential used inrunmng them without resort to moving parts. It is well known that such atube exhibits at starting a high negative-electrode resistance, whichrequires to be broken down by a high potential discharge from aninduction-coil or other suitable source, or else the two terminalsof thecircuit have to be directly connected together through the mercury inthe tube and the circuit so established subsequently interrupted insidethe tube in any suitable manner by moving the lamp or one of itsterminals, whereby the mercury-lamp is started," after which theline-potential will maintain the suitable current-How.

Myinvention consists of a device in which the positive and negativeelectrodes are primarily in electrical contact, s'o that in start'-ing`the current flows through the lamp by conduction, and in which theautomatic effect of the current thus flowing is to separate or renderdefective the contact of the said'electrodes, (by reason of thevaporization of the mercury-electrode,) whereby the negativeelectroderesistance is broken down and the started. ile I have shown my inventionapplied for starting with low 'or normal potential, I do not intend toso limit myself, as my invention permits a wide range of startingvoltage. I Will describe my invention with reference to the accompanyingdrawings, in which- Figure 1 is an illustration of a tube containing myinvention.^ Figs. 2 to 13 are different formsof starting devices, allembodying the broad principles of my invention.

Referrin to Fig. 1, T is a vapor-tube of any suitab e construction. land 2 'are the positive and negative terminals, respectively. 3 is anauxiliary positive terminal normally in contact with the" negativeterminal, as herelam inafter described, and 4 is a suitable device,

which is sealed a platinum wire inclosed in` glass, as indicated at 5.The wire is sealed into the glass for a suflicient length to insure thepreservation of the high vacuum of the tube. Below the seal the tube isenlarged, as

at 7, forming a chamber surrounding the wire and opening by a passage 8into the space above lthe negative mercury-terminal, (indicated at N.)The lower portion of the tube 5 is contracted to forni a passage, whichI prefer to make of such cross-section as will give a lowcarnving-current capacity as compared to that. of the platinum wire.'The platinum Wire 3 extends down to and is Just in contact with thesurface of the mercury, as

indicated. A flow of current of suitable volurne through the wire 3 willstart at the point of contact thereof with the mercury-terminala centerof ebullition, from which mercury-vapor will be given oif and therequisite lseparation of the terminals necessary for starting effected,the vaporized mercury passing out into the main receptacle through theopening 8 and being replaced by the flow of mercury through thecontracted passage 9. There is thus established a suitable condition ofmercury-vapor within the tube, and the center of ebullition constitutesa break in the electrode resistance, so that the applica- '.tion of thenormal potential to the main terminals 1 and 2 is sufhcient to start thetube in operation. f

Fig. 3 shows a modified form of the construction in which lthe platinumor other wire just touches the surface of the negative electrode, andFig. 4 shows a similar construction in a different form.

Figs. 5 and 6 'show constructions analogous to those of Figs. 3 and 4,except that the passage communicating with the chamber between theauxiliary-terminal inclosure and the space above the ne ative electrodeis in the form of a slit extending below the surface of the negativeelectrode for a considerable distance, but a short distance only aboveit. By this means a` difference of vapor tension is created between theinclosure 7 and that' of the tube, whereby a suitable level of the Ielectrode material within the space 7 is preserved, so that the rate ofdisengagement of vapor may be controlled. Where the slits 8 areemployed, the protecting inc-losure may be closed at the bottom.

The illustrations Figs. 2 to 6 show various forms in which the out ut ofmercury-vapor depends on and is regu ated by the difference of level ofthe mercury without and within the auxiliary-electrode inclosure, andthe small size of assage in the latter and of the columns of t eelectrode material inelosed l therein.

Figs. 7 to l() show somewhat different constructions from those inpreceding figures in that the auxiliary terminal is sealed into theinclosure throughout its length, as in Fig. 10, or has only capillaryspaces in which a vapor tension may exist, but in which the mercury andother electrode material will not rise, as shown in Figs. 7, 8, and 9.In these constructions the inclosure is indicated as variously groundaway at its ends flush with the end of the auxiliary terminal, wherebycontact is established with the extreme end of the terminal only, eventhough the mercurylevel may be somewhat higher than the end of theauxiliary terminal, while owing to the shape of the inclosure the vaporescapes freely to the space above the negative electrode. In the case ofthe construction of Figs. 7, 8, and 9 this is assisted by the presenceof the vapor in the capillary space 10.

In Figs. 11 and 12 I show an auxiliary inclosure 11, extending somedistance above and below the surface of the negative-electrode materialused for the purpose of protecting the auxiliary terminal, so far aspossible, from rise and fall of level of the negativeelectrode materialdue to billows or ripples on its surface, which may be caused byebullition at the point of'contact of the auxiliary terminal. Thisbillow protector may be opened or closed at its ends; but in the lattercase it is provided with a slot 12 of sufficient extent to permit of-asufficient inflow of electrode material and the escape of vapor. Thisslit may also advantageously be employed whether the billowprotector beor be not closed at its ends.

Where convenient, the negative-electrode end of the tube mayadvantageously be constructed in substantially spherical form with thecontact-surface of the auxiliary terminal at the centerin order toinsure contact with the tube in varying positions.

In Fi 13 I show a modification in which the auxi iary terminal ends in afine wire dipping into the mercury and having a carrying capacity sosmall that the current-flow through it will heat it to incandescence.Thisv may extend into` the mercury any desired distance and will startthe lam by causing vapor to be given 0H aroun the wire; but I preferthat it enter a short distance only, as a more, active center ofebullition is then formed.

It is obvious that when the tube is once started the auxiliarystarting-circuit may, if desired, be cut out by suitable means-as, forexample, the hand-switch 4a. (Shown in Fig. 1.)

Where alternating currents are employed, the auxiliary terminal mayadvantageously be left in circuit and the current-controlling device 4,Fig. 1, be a reactance-coil 4a or a device tending also to shift thephase of the current.

Having thus described my invention and several forms lf apparatus inwhich it may be embodied in practice, I wish it to be distinctlyunderstood that my claims are not limited to the precise forms shown,but that various modifications and changes vmay be made withoutdeparting from 'the spirit of my invention and without exceeding theI,scope of my claims.

What I claim is 1. In a vapor-tube, the combination with separatedterminals between which a conducting-vapor exists when the tube is inoperation, but a non-conducting and hi hly-resistant interval existswhen the lamp as not been started, a stationary auxiliary terminal innormal contact with one of the terminals of the lamp, said contact beingof low conductance whereby, on the passageof current, a center ofemission of conductive vapor is formed.

2. In a mercury-lamp, the combination with the electrodes thereof fornormally op-v erating the lamp, of an auxiliary electrode in contactwith one of the electrodes of the y.lamp before starting, and meanswhereby the current conducted before starting automatically separates orrenders defective the contact of said auxiliary electrode andlampelectrode, while both remain stationary, whereby the lamp isstarted.

3. .In a vapor-tube the combination of va positive terminal, a liquid neative terminal, an auxiliary starting-termina in limited contact withthe negative terminal and means 'for restricting the free access ofliquid to said auxiliary terminal.

4. In a vapor-tube the combination with the .positive and negativeterminals, of a stationary auxiliary terminal normally in contact with alamp-terminal, one of said terminals being liquid, means for supplying aeurrent through said auxiliary terminal, an means whereby the assage ofsaid current will vaporize the liquid terminal and thereby break saidcontact.

5. In a vapor-tube the combination with a positive and a liquid negativeterminal, of a stationary solid auxiliary terminal normally in contactwith the liquid terminal, means for-supplying a current through saidauxroo iliary terminal, means whereby the passage of said current Willvaporize the liquid terminal and thereby break said contact.

6. In a vapor-tube the combination with the positive and negativeterminals, of a stationary auxiliary terminal normally in contact with alamp-terminal, one of said terminals being liquid, a non-conductingenvelop surrounding said auxiliary terminal whereby contact of theliquid terminal with the side thereof is prevented.

7. In a vapor-tube the combinationl with a liquid terminal, of a solidauxiliary terminal, an inclosure for said auxiliary terminal saidinclosure having a restricted opening communicating with the liquidterminal whereby the access of the latter to the side of the auxiliaryterminal is prevented.

8. In a vapor-tube the combination with a liquid terminal, of a solidauxiliary terminal, an inclosure for said auxiliary terminal, A

said inclosure having a restrictedl opening communicating with theliquidv terminal, and an opening communicating with the space above thenegative terminal whereby the 'access of the liquid terminal to the sideof the auxiliary terminal is prevented and the escape of vapor ispermitted. .l

9. In a vapor-tube, the combination with a liquid terminal, of a solidauxiliary terminal, an inclosure for said auxiliary terminal, saidinclosure having a restricted opening communicating with the liquidterminal, and having a space above said terminal communieating with theSpace above the negative electrode.

10. In a vapor-tube the combination with a positive terminal and aliquid negative terminal of an auxiliary positive terminal sealed intothe wall of the tube for a part of its length and having its end incontact with the negative electrode and a non-conducting inclosurearound said end having an opening into the space above the liquidterminal and having a limited opening into said liquid terminal as andfor the purposes set forth.

1 1. In a vapor-tube, the combination with the liquid terminal of asolid auxiliary terminal, an inclosure for said auxiliary terminalV madeof non-conducting material, said inclosure having a restricted openingcommuni#v eating with the liquid terminal and having a space above saidterminal, communicating with the space above the negative electrode.

12. In a vapor-tube, the combination with a liquid terminal, of a solidauxiliary terminal, an inclosure for said auxiliary terminal, saidinclosure having a space above the liquid terminal and a passage fromsaid inclosure opening below the level of the liquid terminal, whereby alimited rate of flow of the liquid to said solidzterminal is permitted.

13. In a vapor-tube, the combination with a liquid terminal, of a solidauxiliary terminal, an inclosure for said auxiliary terminal extendingbeyond the end thereof beneath the surface of the liquidterminal,whereby access of the latter to the solid terminal is restricted, andmeans for regulating the flow of said material to replace that vaporizedby the flow of current.

14. In a vapor-tube the combination with a positive and a liquidnegative terminal, of a solid auxiliary terminal normally in contactwith the negative terminal, and an inclosure therefor exposing thepositive terminal to contact with the negative terminal at the endthereof only.

15. In a vapor-tube the combination with a positive and a liquidnegative terminal, of a solid auxiliary terminal normally in contactwith the negative terminal, a tube of non-conducting materialsurrounding said solid terminal, said tube having a restricted openingfilled with negative-electrode material in contact with the auxiliaryelectrode.

16. In a vapor-tube a liquid negative electrode, an auxiliary positiveterminal and av non-conducting inclosure therefor, having a space withinsaid inclosure above the negative-electrode surface, and means forregulating the inflow of liquid and outflow of vaor. v p 17. In avapor-tube a liquid negative electrode, an auxiliary positive terminaland a non-conducting inclosure therefor, having a space within saidinclosure above the nega-A tiveelectrode surface and a restrictedopening in said inclosure extending above and below the surface of theliquid terminal and regulating the infiow of liquid and outflow ofvapor. In testimony whereof I have signed my name to this specificationin the presence of two subscribing witnesses.

Y THEoDoRE BoDDE.

Witnesses I W. A. PAULING, G. A. ROEDER.

IOO

